Proceedings of the 26th Annual Meeting, Southern Soybean Disease Workers (March 20-22, 1999, Robinson, Mississippi)

Contents Soybean Disease Loss Estimates for the Southern United States during 1998. Phillip W Pratt Treasurer report. Peggy S King Contributed paper session Resistance Ratings for 288 soybean Cultivars to the Reniform Nematode, Rotylenchulus reniformis. RT Robbins, L Rakes, and L Jackson Evaluation of Azoxystrobin on Two Foliar Soybean Diseases in Arkansas. CM Coker Early Soybean Production System in Missouri: Progress and Potential. JA Wrather, and DA Sleper A New Phomopsis Disease of Soybeans in Mississippi. GL Sciumbato and BL Keeling Reaction of Soybean Genotypes to Sudden Death Syndrome. JH Klein, ME Schmidt, RE Whelan, JS Russin, RJ Suttner, MA Shenaut, and PT Gibson Additional Studies on the Use of Soybean as a Rotation Crop for the Management of Root-knot Nematodes in Peanut. CF Weaver, R Rodriguez-Kabana and CR Taylor Comparison of Soybean Meal with Other Legume Meals as Amendments to Soil for Control of Plant-Parasitic Nematodes. PS King, R Rodriguez-Kabana, and CR Taylor Tolerance of Selected Roundup Ready Soybean Cultivars to Columbia Lance Nematode. SR Koenning Proceedings of the Southern Disease Workers are published annually by the Southern Soybean Disease Workers. Text, references, figures, and tables are reproduced as they were submitted by the authors. The opinions expressed by the participants at this conference are their own and do not necessarily represent the views of the Southern Soybean Disease Workers. Mention of trademark or propriety products in this proceedings does not constitute a guarantee, warranty, or endorsement of that product by the Southern Soybean Disease Workers

Proceedings of the 27th Annual Meeting, Southern Soybean Disease Workers (April 6-8, 2000, Fort Walton Beach Florida)

Contents Southern United States Soybean Disease Loss Estimate for 1999. Compiled by SR Koenning Treasury report. Peggy S King Invited presentation Bean Pod Mottle: A Soybean Disease on the Rise in the New Millennium. SA Ghabrial Contributed papers Response of Selected Mid-South Soybean Varieties to the Reniform Nematode. GW Lawrence, KS McLean, and SM Baird Field Response of Soybean Cultivars to the Reniform Nematode Rotylenchulus reniformis. PS King, DB Weaver, and R Rodriguez-Kabana Approaches to Race Determination in Soybean Cyst Nematode. AJ Palmateer, ME Schmidt, SR Stetina, and JS Russin Nematological Survey of Selected Soybean and Cotton Fields in Alabama. DG Robertson and R Rodriguez-Kabana Soybean Meal-Based Compositions as Organic Amendments for Control of Plant-Parasitic Nematodes. CF Weaver and R Rodriguez-Kabana Cell Selection Approach for Generating Soybean with Resistance to Macrophomina phaseolina. NA Reichert, GL Sciumbato, S-H Lin, L Chen, BL Keeling, and AL Woods Identification of Molecular Markers Linked to a New Gene Conferring Resistance to Frogeye Leaf Spot in \u27Peking\u27 Soybean. W Yang, DB Weaver, J Qiu, and B Nielsen Soil Physical, Chemical, and Biological Properties Associated with Sudden Death Syndrome in Southern Illinois. JP Bond, AJ Hoskins, CM Vick, SK Chong, and JS Russin Response of Soybean Sudden Death Syndrome to Amelioration of the Soil Physical Environment. CM Vick, SK Chong, JP Bond, and JS Russin Differential Enzyme Activity in Two Soybean Cultivars Resistant and Susceptible to Sudden Death Syndrome. SA Bates, DA Lightfoot, O Myers, Y Luo, and JS Russin Evaluation Of Azoxystrobin On Soybean Disease, Yield, and Seed Quality. KS McLean, GW Lawrence, L Carter, and L Campbell Soybean Disease Loss Estimates for the United States from 1996-1998. JA Wrather and WC Stienstra Proceedings of the Southern Soybean Disease Workers are published annually by the Southern Soybean Disease Workers. Text, references, figures, and tables are reproduced as they were submitted by authors. The opinions expressed by the participants at this conference are their own and do not necessarily represent those of the Southern Soybean Disease Workers. Mention of a trademark or proprietary products in this proceedings does not constitute a guarantee, warranty, or endorsement of that product by the Southern Soybean Disease Workers

Proceedings of the 30th Annual Meeting, Southern Soybean Disease Workers (March 3, 2003, Little Rock, Arkansas)

Contents Southern Soybean Disease Workers 2002 treasury report. James Bond United States Soybean Disease Loss Estimate for 2002. Compiled by Stephen R. Koenning Evaluation of Reduced Rates and Timing of Azoxystrobin on Frogeye Leaf Spot Cliff M Coker Effect of Fungicides on Soybean Disease, Yield and Seed Quality. RW Schneider, JD Siebert, CA Jones, and JL Griffin Effect of Fungicide Seed Treatment on Soybean Establishment. ML Rosso, C Boger, G Bates, C Rothrock, T Kirkpatrick, and J Rupe Influence of Soybean Cyst Nematode on Sudden Death Syndrome Development in Field Microplots in Arkansas. SL Giammaria, CB Boger, and JC Rupe Possible Mechanism for Resistance to Pythium spp. in the Soybean Cultivar Archer. GD Bates, CS Rothrock, and JC Rupe Late Season Diseases Have Major Impact on Soybean Crop in Mississippi in 2001 and 2002. GL Sciumbato and Alemu Mengistu Identification and Characterization of Soybean Germplasm with Resistance to Seed Infection by Phomopsis longicolla and Cercospora kikuchii. Eric W Jackson, P Fenn, and PK Miller Soybean Green Stem Caused by Selected Strains of BPMV. You-Keng Goh, Said A Ghabrial, John S Russin, and Jason P Bond Meloidogyne incognita, Moving on to Greener Pastures. Jonathan B Allen, Jason P Bond, and Michael E Schmidt Proceedings of the Southern Soybean Disease Workers are published annually by the Southern Soybean Disease Workers. Text, references, figures, and tables are reproduced as they were submitted by authors. The opinions expressed by the participants at this conference are their own and do not necessarily represent those of the Southern Soybean Workers. Mention of a trademark or proprietary products in this publication does not constitute a guarantee, warranty, or endorsement of that product by the Southern Soybean Disease Workers

Performance of Blends of Soybean Cyst Nematode Resistant and Susceptible Cultivars

Use of soybean cyst nematode (SCN), (Heterodera glycines Ichinohe), resistant cultivars of soybean [Glycine max (L.) Merr.] is common practice to control losses due to this pest. The experiment was conducted to compare blends of resistant and susceptible cultivarswith their yield response when grown in pure monoculture stands. Two SCN-resistant cultivars Bedford and Bradley, three susceptible cultivars or breeding lines, Essex, York, and N79-491, and blends of resistant and susceptible cultivars (50:50 ratio) were tested against soybean monoculture in a SCN Race 14-infested field. The mean yield (over 5 yr) of Bedford, Bradley, Essex, York, and N79-491 grown in monoculture was 1707, 1703, 903,1063, and 1379 kg ha−1, respectively. Yield of blends were generally similar to their resistant cultivar components in monoculture but they were always greater (P = 0.05) than the susceptible cultivar components. The Bedford and Essex blend resulted in the greatest yield, which was 672 kg ha−1 (51%) greater than the mean of component crop yields in pure stand. The race designation of the SCN population changed from Race 14 to Race 5 when resistant Bedford and Bradley were grown, from Race 14 to 9 when susceptible cultivars were grown, and from Race 14 to 2 in plots containing blends of resistant and susceptible cultivars or lines. Resistant cultivars grown with susceptible cultivars or lines in blends had lower numbers of cysts on the roots 30 d after planting than resistant cultivars grown in pure stands. Blends of resistant and susceptible cultivars can maintain soybean yields at acceptable levels by minimizing the selection pressure on the nematode population for their ability to parasitize resistant cultivars

Effect of temporal deployment of different sources of resistance to soybean cyst nematode

Thirteen rotation treatments consisting of 'Bedford', a soyabean cultivar resistant to Heterodera glycines (SCN) races 3 and 14, 'Forrest' resistant to races 1 and 3, susceptible 'Essex', and a nonhost crop (cotton [Gossypium hirsutum]) were evaluated in an SCN infested field for 4 yr in Portageville, Missouri. Yields of soyabean cultivars in continuous production systems were compared with those in rotation with the nonhost, resistant, and susceptible cultivars. Bedford and Forrest yields, over the 4 yr, were less variable than Essex yields. Forrest and Essex produced similar yields in 3 out of 4 yr, and yields of Essex were significantly lower than Bedford yields in 2 out of 4 yr. Beneficial effects of different rotations on cultivar performance were not very conspicuous, however, yields of Essex were increased with rotation in 5 of the 6 comparisons compared with continuous Essex, whereas Bedford in rotation was significantly higher than continuous Bedford in 2 of the 5 comparisons. Grain yields of Forrest were not affected by rotation systems. The nematode density, after 4 yr, was lowest in cotton-Forrest-Bedford-cotton system and greatest in Bedford-cotton-Essex-Forrest system. The preceding crop had a greater influence on the nematode population density than the rotation system per se. Treatments with cotton as the preceding crop had lower nematode population densities than resistant or susceptible soyabean. Rotating cultivars caused changes in SCN race structure. SCN race 14 was present in almost all rotations including Essex and Forrest. Bedford tended to increase the population with genes for parasitism on PI 88788, resulting in a shift to race 4. The shift to highly pathogenic race was slower in rotations that included susceptible Essex and Forrest as a component crop. Inclusion of susceptible soyabean lines in rotations may delay, but not prevent, the development of highly virulent races of SCN. Rotation of soyabean cultivars was found to be a useful practice in the management of SCN-caused losses

A Coordinated Effort to Manage Soybean Rust in North America: A Success Story in Soybean Disease Monitoring

Existing crop monitoring programs determine the incidence and distribution of plant diseases and pathogens and assess the damage caused within a crop production region. These programs have traditionally used observed or predicted disease and pathogen data and environmental information to prescribe management practices that minimize crop loss (3,69). Monitoring programs are especially important for crops with broad geographic distribution or for diseases that can cause rapid and great economic losses. Successful monitoring programs have been developed for several plant diseases, including downy mildew of cucurbits, Fusarium head blight of wheat, potato late blight, and rusts of cereal crops (13,36,51,80)